the most consistent behavior that stands out from infiltrators (usually in retrospect) is that they're gossips. they share info they don't need to (including personal!) with the hopes that you'll do the same or that they'll at least be able to introduce personal friction.
i personally wouldn't take gossiping as conclusive evidence that someone is a cop, but you should definitely take it seriously as the kind of shit cops do to make our work harder and so is unacceptable regardless of whether any individual actually is a cop
any way, trueanon did a good interview with a guy who's group got infiltrated
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